|
|
Parrot News17 September 2009 Spatial distribution and physical characteristics of clay licks in Madre de Dios, Peru A project report available here by: Donald J. Brightsmith, Gabriela Vigo and Armando Valdés-Velásquez Abstract: Many birds and mammals throughout the world consume soil. Recent studies have suggested that the western Amazon basin and specifically the Department of Madre de Dios, Peru have very high numbers of these soil consumption sites. In this region, soil consumption is common among birds (parrots, guans, and pigeons) and mammals (ungulates, rodents, and primates). Many of these species belong to families with large numbers of threatened and endangered species (parrots, guans, and primates). Other species play important roles in seed dispersal or play keystone roles in tropical forest dynamics (ungulates and large primates). Many individuals of these species congregate daily at clay licks where they can provide a valuable attraction for tourists or be exposed to local hunters. As a result, effective management of clay licks is important for the conservation of healthy rainforest ecosystems in this region. The reasons why these animals eat soil have been studied extensively and likely relates to a need for sodium or possibly protection from dietary toxins. In the current study we surveyed parts of five rivers (Piedras, Amigos, Madre de Dios, Colorado, and Tambopata) and found clay licks using a mixture of chance encounters, help from local people, and systematic transect surveys. The transect surveys were conducted along river and stream edges and proved an efficient and effective way to determine the relative abundance of clay licks in different areas. We found 152 clay licks and recorded 14 mammalian and 25 avian taxa using these licks. The most common species were paca, tapir and red brocket deer among the mammals and Cobalt-winged Parakeet, Mealy Parrot and Red-and-green Macaw among the birds. As expected we found the typical large river bank cliffs used by hundreds of parrots and macaws and the typical wide shallow holes in the forest floor used by hundreds of white-lipped peccaries, tapirs and other ungulates. However, we also found many small clay licks apparently used by a few pacas and other rodents. The mammal species most often use clay licks within the habitats they use normally. For example tapir, deer, and white-lipped peccary used licks inside the forest while capybara preferred river edge licks. Tapirs used low licks with little vegetative cover while pacas and white-lipped peccaries used low licks with high vegetative cover. Parrots used large, high licks with lower vegetative cover along the river edge, presumably to reduce the threat of predation. Lick abundance varied significantly among the river areas surveyed with lick density being highest in the north (Piedras River with > 1 lick per km of transect) and lowest in the south (Tambopata River ~0 licks per km of transect). Reasons for the difference in lick abundance may be due to the types of river systems surveyed with higher gradient rivers containing less clay licks. Ecotourism companies used only about 10% of all licks, including < 30% of the parrot clay licks and < 40% of all large macaw clay licks. This shows that the ecotourism industry has not saturated this resource. Hunters were only detected at 6% of the clay licks and we found no evidence of large scale market hunting at the licks we visited. We are sure we underestimated the number of licks visited by hunters during their walking routes, but our finding suggests that large scale market hunting by hunters waiting at clay licks is uncommon in the region. In summary, this study shows that clay licks are very common in the region and that most remain lightly exploited or not exploited by humans. This means that there is still time to protect these important resources through a mixture of protected areas, tourism management, and community-based management of hunting.
|
|